I wrote: "A couple meters of rubber hose can not radiate away 80% of
12 kW of heat suggested to be produced in the original runs."
To be more specific, it can be expected the heat flow through the
rubber tube walls is about 220 W per m of hose.
Using the thermal conductivity for rubber at about 0.14 W/(m K):
http://www.monachos.gr/eng/resources/thermo/conductivity.htm
a roughly 1 cm radius (i.e. 0.0628 m circumference) hose with 0.2 cm
walls, across a 75 K thermal differential we have:
Heat flow = (0.14 W/(m K))*(1 m)*(0.0628 m)*(75 K)/(0.002 m) = 330 W
per meter of tubing. However, the thermal differential of 75 K is
greatly exaggerated because achieving that would require water
cooling of the tube exterior at 25 °C. More likely the external
temperature of the hose is at about 75 °C, giving a differential of
50 K, and a heat flow of 220 W per meter of hose, or about 440 W for
2 meters of hose.
At 615.6 Wh/kg that 440 W provides a condensation rate of about 0.714
kg/hr, or 0.2 g/s, or 0.2 cc water/s.
This condensation can be essentially eliminated by insulating the
rubber hose.
The thermal conductivity of copper is 386 W/(m K), about 2700 times
that of rubber. Several meters of similar sized copper pipe coiled a
barrel of water at 75 C should easily condense 12 kW of steam.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
